Numerous high-profile journalists had no qualms about claiming that Mario Kart 8 was the most visually appealing current-gen game this time last year, so I don't see why Zelda should be different. It's not like it has to be the new standard for 8th-gen visuals or anything, it just has to look... well, as good as any other first-party Wii U title to date.
If Zelda looks better than Mario Kart, then it stands to reason that in the eyes of anyone who claimed that MK8 was the prettiest 8th-gen game last year that it also looks better than Ryse or Infamous: SS.
Actually, it wasn't even "this time last year." Here's a clip of Jared Petty from IGN about 7 months ago saying "Mario Kart 8, for my mind, is the best-looking game of the current generation right now."
